State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China.
State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, East China University of Science and Technology, Shanghai 200237, China.
J Hazard Mater. 2015 Apr 9;286:7-14. doi: 10.1016/j.jhazmat.2014.12.031. Epub 2014 Dec 19.
Thermal activation of persulfate (PS) has been identified to be effective in the destruction of organic pollutants. The feasibility of carbon tetrachloride (CT) degradation in the thermally activated PS system was evaluated. The experimental results showed that CT could be readily degraded at 50 °C with a PS concentration of 0.5M, and CT degradation and PS consumption followed the pseudo-first order kinetic model. Superoxide radical anion (O2(-)) was the predominant radical species responsible for CT degradation and the split of CCl was proposed as the possible reaction pathways for CT degradation. The process of CT degradation was accelerated by higher PS dose and lower initial CT concentration. No obvious effect of the initial pH on the degradation of CT was observed in the thermally activated PS system. Cl(-), HCO3(*-), and humic acid (HA) had negative effects on CT degradation. In addition, the degradation of CT in the thermally activated PS system could be significantly promoted by the solvents addition to the solution. In conclusion, the thermally activated PS process is a promising option in in-situ chemical oxidation/reduction remediation for degrading highly oxidized organic contaminants such as CT that is widely detected in contaminated sites.
过硫酸盐（PS）的热活化已被证明可有效破坏有机污染物。评估了热活化过硫酸盐体系中四氯化碳（CT）降解的可行性。实验结果表明，在 50°C 时，PS 浓度为 0.5M 时，CT 可迅速降解，CT 降解和 PS 消耗遵循拟一级动力学模型。超氧自由基阴离子（O2(-))是降解 CT 的主要自由基物种，提出 CCl 的分裂是 CT 降解的可能反应途径。较高的 PS 剂量和较低的初始 CT 浓度会加速 CT 的降解过程。在热活化过硫酸盐体系中，初始 pH 值对 CT 降解没有明显影响。Cl(-), HCO3(*-), 和腐殖酸（HA）对 CT 降解有负面影响。此外，向溶液中添加溶剂可显著促进 CT 在热活化过硫酸盐体系中的降解。总之，热活化过硫酸盐工艺是原位化学氧化/还原修复中降解高度氧化有机污染物（如 CT）的一种很有前途的选择，CT 在污染场地中广泛检出。
